I get asked whether to use affect or effect all the time, and it is by far the most requested grammar topic, so I have a few mnemonics and a cartoon to help you remember.

What Is the Difference Between Affect and Effect?

Before we get to the memory trick though, I want to explain the difference between the two words: The majority of the time you use affect with an a as a verb and effect with an e as a noun.

When Should You Use Affect?

Affect with an a means "to influence," as in, "The arrows affected Aardvark," or "The rain affected Amy's hairdo." Affect can also mean, roughly, "to act in a way that you don't feel," as in, "She affected an air of superiority."

When Should You UseEffect?

Effect with an e has a lot of subtle meanings as a noun, but to me the meaning "a result" seems to be at the core of all the definitions. For example, you can say, "The effect was eye-popping," or "The sound effects were amazing," or "The rain had no effect on Amy's hairdo."

Common Uses of Affect and Effect

Most of the time, affect is a verb and effect is a noun.

There are rare instances where the roles are switched, and I'll get to those later, but for now let's focus on the common meanings. This is "Quick and Dirty" grammar, and my impression from your questions is that most people have trouble remembering the basic rules of when to use these words, so if you stick with those, you'll be right 95% of the time.

So, most of the time, affect with an a is a verb and effect with an e is a noun; and now we can get to the mnemonics. First, the mnemonic involves a very easy noun to help you remember: aardvark. Yes, if you can remember aardvark—a very easy noun—you'll always remember that affect with an a is a verb and effect with an e is a noun. Why? Because the first letters of "avery easy noun" are the same first letters as "affect verb effect noun!" That's avery easy noun. Affect (with an a) verb effect (with an e) noun.

"But why Aardvark?" you ask. Because there's also an example to help you remember. It's "The arrows affected Aardvark. The effect was eye-popping." It should be easy to remember that affect with an a goes with the a-words, arrow and aardvark, and that effect with an e goes with the e-word, eye-popping. If you can visualize the sentences, "The arrows affected the aardvark. The effect was eye-popping," it's pretty easy to see that affect with an a is a verb and effect with an e is a noun.

The illustration of the example is from my new book. It's Aardvark being affected by arrows, and I think looking at it will help you remember the example sentences; and it's cute. You can print it out and hang it by your desk.

So avery easy noun will help you remember that affect with an a is a verb and effect with an e is a noun, and the example will help you see how to use both words in a sentence.